1. Field of the Invention
The invention relates to radio frequency technology and particularly to power management arrangements used in radio and microwave frequency ranges.
2. Description of the Related Art
Power dividers/combiners operating in high frequency ranges are used either to divide or combine radio and microwave signals. A power divider typically comprises an input port and two output ports. The power to the input port is distributed to the output ports evenly or in another proportion. In a power combiner, several input signals are combined into one output signal.
A power divider/combiner according to the prior art is represented by what is called a Wilkinson power divider/combiner. In a conventional Wilkinson power divider/combiner, there is a conductive pattern upon an insulating substrate structure, such as a printed board. The conductive pattern comprises transmission lines of a length of λ/4 between the input port and the output ports. Qualities required of power dividers/combiners include small power losses, sufficient insulation between the transmission lines and sufficient EMC protection.
However, the Wilkinson power dividers/combiners according to the prior art are large in size and take too much space from the surface layer of the printed board in order for them to be integrated into recent devices requiring increasingly small components. It is difficult to reduce the size of the Wilkinson power dividers/combiners without, for example, deteriorating the insulation between transmission lines and increasing power losses too much.
Thus, a need has arisen for such Wilkinson power dividers/combiners operating in high frequency ranges which would take only a little space from the surface layer of the printed board and in which power losses would also be small and the insulation between transmission lines and the electromagnetic protection of the power divider towards the surroundings would be good.